Controversial charges at the Dartford Crossing are set to become permanent.

When the tunnels were first built, the government promised that charges would be scrapped once all the works had been paid for.

However the new transport secretary, Grant Shapps, has decided that the charges will continue in order to "manage traffic demand".

A spokesperson for the department said: "The current charge to use the crossing exists to manage traffic demand on a crossing where traffic exceeds capacity.

"If the charge ended, there would be an increase in traffic and congestion on this important strategic route with knock-on congestion on local roads as usage of the Crossing increases."

The Department of Transport says the crossing is at 117 per cent capacity, with 160,000 daily crossings.

In February 1999 the Government announced the bridge would be paid for by the end of 2003, ending the charge, but backtracked on the decision in 2001.